Shipyard

ABSTRACT

A shipyard for constructing a work unit or units to be completed by a combination of a plurality of process steps, comprising a strip of conveying section which is equipped with conveying equipment, and specialized shop sections for performing the individual process steps having sufficiently wide entrances on the sides facing said strip of conveying section through which the conveying equipment and/or a work unit or units can enter or leave the individual shop sections, said specialized shop sections being so located as to surround said conveying section.

United States Patent 11 1 Kawasaki July 24, 1973 SHIPYARD 2,245,486 61941 Little 114 65 R x 2,379,259 6/1945 Smith..... 114/65 R x [75]Invent Masah'm Kawasak" Nagasak" 3,363,597 1/1968 Zeien 114/65 R Japan3,478,525 11 1969 Van Der Hoeven 114 65 R x Assigneez J gy Kabushiki3,487,807 Van D61 Hoeven R X Kaisha, Tokyo, Japan Filed: Jan. 18, 1971Appl. No.: 107,262

Foreign Application Priority Data Jan. 23, 1970 Japan 45/6125 US. Cl.29/200 A, 114/65 R, 214/16 B Int. Cl 823p 19/00 Field of Search 114/65R, 65 A, 77;

References Cited UNITED STATES PATENTS 3/1942 Mertzanoff et a1. 104/48 X6/1966 Burnett 214/16 B X 10/1954 Lontz 2l4/16.1A X

Special Shop Specialied Shop Convey,

Means Conveying Section Material Collecting Special Shop DischargeSection Primary Examiner-Gerald M. Forlenza Assistant ExaminerFrank E.Werner Attorney-George B. Oujevolk [57] ABSTRACT 1 Claim, 2 DrawingFigures Material Collecting Material Collecting Specialized Shop SectionMoleriol Discharge Seclion Collecting Special Shop h f2 b MaterialSpeclollod Collecting Shop Convoy Moons Conveying Section Convey MeansSpecialized Shop Moloriol ColloCling Spore Section Special ShopDischarge g Welding Soction Shops I I I I I Plole Joinling Section 11 9493 92 91 82 81 2 Conveying Section Truck E g 235 ihg 1 l1 5 3 Shop BoomShop 102 101 12 '72 71 6 4 n i l I l I 1 I 1 Cooling Spore Assembly BeamShops Section Shops Asaorlinq Shop /6/9 in Aim/01,19 A;

INVENTOR.

SHIPYARD BACKGROUND OF THE INVENTION This invention relates to a novellayout of a shipyard for the construction of hulls.

In recent years, there has been a tendency among shipyards which arebuilding steel ships to adopt a system similar to the assembly lineproduction systems of other industries for the quantity production of alimited number of products, and, in this way, unitary blocks whichconstitute certain parts of a hull or hulls are constructed by varioussingle-purpose machines with a high degree of overall efficiency.According to the system, blocks to be worked are placed on a conveyorand many different single-purpose machines are arranged alongside theline so that the blocks can be progressively worked and finished as theyare conveyed forward.

The above system is gaining popularity because it is free from theuncertain factor of transfer of blocks as by cranes which is dictated bythe environmental conditions of the shops. Moreover, it is beneficial inavoiding the great economic disadvantage of installing in scatteredareas the very large and expensive single purpose equipment for handlingsuch large structures as hull blocks.

However, the shipbuilding industry has the following problems. In theshipbuilding, the stages of work involved in the construction of unitaryblocks that can be automatated or mechanized are only few and they areby nature relatively simple and yet require manual work between thestages. Another factor to be taken into consideration is that ships inmost cases are built on individual orders to particular specificationsand even ships of the same design can differ materially in theconstruction of the blocks and the work procedure to be employed. As aresult, the overall amount of work that is executed by the individualsingle-purpose machines varie s much with the blocks. Thus, the work onblocks once placed on a conveyor is governed by the specific block thatdemands the largest amount of work and it is difficult to convey all ofthe blocks at a constant speed with the same number of workers assignedalong the line. Actually, therefore, the number of workers must bechanged from time to time in an effort to synchronize the operations forthe individual blocks. In addition, the workers posted to the stationsbetween the automated or mechanized stages are often forced to stand bywith no work to do or move to different positions.

SUMMARY OF THE INVENTION The present invention has been perfected aftera diversified study of the foregoing disadvantages of the layout ofordinary shipyards, and by an intensified effort to develop a lineproduction system for a shipyard that can best meet the requirements forshipbuilding. The invention thus has for its object the creation of ashipyard which permits'a remarkable saving of installation cost andextremely efficient shipbuilding through elimination of all operation(transfer) conveyors and which also is adapted to every possibleconditions'of location to be encountered and is capable of fullutilization of a minimum of land space.

Briefly, the invention provides a shipyard in which a linear conveyingsection having conveying equipment for linear transfer, such as transfertrucks which travel on rails, cranes, or the like, is surrounded byindividual shop sections for specialized processing stages havingentrances through which the conveying equipment and/or the work to behandled is moved in and out, and the work units fabricated, manufacturedor worked in the individual shop sections are transported by conveyingequipment sequential shop sections, in such a manner that the operationsfrom the starting stage to the last stage are carried out in successionin those specialized shop sections and the work units that have gonethrough the entire operations are carried by conveying equipment out ofthe specialized shop sections.

Many advantages including the following can be expected of a shipyard ofthe layout according to this invention:

l. The variation in the amount of work caused by the difference of thestructure and size of work units being handled is always absorbed by theretension time under control in the individual specialized shopsections.

2. The number of specialized shop sections can be suitably chosendepending on changes in the size of the work units and in the amount ofwork required.

3. In constrast to ordinary shipyards which must be provided with extraspace for each shop or area for specialized operation, the shipyard ofthis invention requires only a minimum number of extra areas which maybe used in common with the specialized shop sections.

4. In conventional shipyards where the so-called stationary work systemis adopted, a finished work unit must be transported over another workunit or units in process. This necessitates a conveying equipment suchas a crane of sufficiently high lift, and demands high building costwhere the operation is to be performed within a building. In a shipyardof the invention, by contrast, there is no necessity for carrying a workunit above any other unit and, therefore, the initial investment is low.

5. In general a work unit is constructed of members of different types,and the limitations of shipyard buildings and cranes for carrying themembers in and out of the fabrication area render it difficult toaccumulate and distribute the materials freely as desired. In theshipyard embodying the invention, only the flow of members from varioussource stages has to be considered, and the arrangement may be freelymade so that conveyance of the members into specialized shop sections iscarried out without mutual interference of the material supplies. Thusthe flow of materials is simplified.

6. A work unit may be transferred to a subsequent station at any timedesired provided that the shop where the subsequent operation isperformed has room for it. Therefore, the work unit can be finished byvarious specialized equipment so as to meet the delivery requirement, indisregard of the amount of work involved.

Other objects, advantages and features will become apparent from thefollowing detailed description taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a basic layout plan of ashipyard according to the invention; and

FIG. 2 is a layout plan of plants for the construction of flat blocksand for the surface treatment of steel products in a shipyard of a moreunitary layout than in FIG. 1.

DETAIL OF THE INVENTION The embodiment of FIG. 1 represents a basiclayout of a shipyard in accordance with the invention.

In the FIG., there is shown a strip of conveying sec tion i as having apair of conveying means i, and i for linear movement, e.g., transfertrucks or cranes. Along both sides and at one end of this section i,there is arranged material collecting sections a, b and c, ecializedshop sections d, e,f, g and h, a discharge section j and a spare sectionk.

The material collecting sections a to c are provided for collection ofmembers necessary for the completion of work units, classifying themembers by types and properties. In the specialized shop sections d toh, the respective process steps are carried out to work and finish thematerials to final products. The discharge sectionj is for dischargingthe finished work units, and the spare section k is for temporarilystoring a work unit or units from a process stage before beingtransferred to the subsequent stage as long as the subsequent stage isstill occupied by a preceding work unit or units.

The material collecting sections a, b and c, specialized shop sections11, e,f, g and h, discharge sec tionj and spare section k have entranceson the sides adjoining the conveying section i, and through thoseentrances the conveying means i, and i and work units can be moved inand out of those sections, or work units can be moved in and out of theconveying means i, and i Also as can be seen from FIG. 1, thespecialized shop sections d andfmay be further divided into pairs ofspecialized shop sections 11,, d, and f,, f, depending on the sequenceof the operation cycles to be performed in those shop sections. It isalso possible to provide additional specialized shop sections wherenecessary.

Manufacture of a work unit or units is carried out in a shipyard of theforegoing layout in the following way. The members necessary to completethe particular work unit are taken out, according to the properties ofthe members, from the collecting sections a, b and c, by means of theconveying means i, or i,,. The members are then carried into thespecialized shop section d, particularly into the specialized shopsection d, in the case of the layout shown in FIG. 1, where the membersare fabricated and worked. Upon completion of the work in thespecialized shop section d, the work unit is sent to the nextspecialized shop section e, where it is further worked. Thence it iscarried by the conveying means i, or i over to the specialized shopsection f, or f for the subsequent working.

In the similar way, on completion of the work in the specialized shopsection f, orf the work unit is further conveyed by the conveying meansi, or in succession to the specialized shop sections g and h for furthernecessary operations. After the completion of the entire work forfabrication, machining, etc., the work unit is carried by the conveyingmeans i, or i to the discharge section j and thence out of the shopsection.

In the plant layout described above, the spare section k is intended fortemporary storage of a work unit or units which, after the completion ofwork in a certain specialized shop section, are to be conveyed to a nextspecialized shop section and must be held in the standby positionbecause the preceding unit or units overstay in the next section. Thespare section k is used in common with all of the specialized shopsections.

In the shipyard according to the present invention, tables, rollers,conveyors, etc. are employed for the conveyance of members, work units,etc. between the shop sections a to h,j and k and the conveying meansi,, The members, work units, etc. are either pulled or pushed formovement by drives installed on the conveying equipment, and there is noneed of providing driving or conveying equipment for each shop section.When using a plurality of conveying means i,, mutual interference of theequipment naturally takes place and, therefore, it is desirable topermit the delivery of work units or provide an exchange facility amongthe conveying means. The conveying means and the installations in theshop sections may be of any conventional types generally in use.

The embodiment shown in FIG. 2 will now be explained. In this embodimentthe basic layout of a ship yard above described with reference to FIG. 1is adopted for a flat block plant of a shipyard.

Generally speaking, flat blocks are constructed of flat plates which arefabricated in a plate-jointing shop, longitudinal strakes fabricated ina longitudinal strake shop, and transverse beams fabricated in atransverse beam shop.

Thus, the flat block plant according to this invention consists ofastrip of conveying section 1 having a transfer truck 1, which travelsstraightly on tracks not shown, surrounded by a generally U-shapedarrangement of shop sections necessary for the construction of flatblocks. Surrounding the conveying section 1 are: a plate-joining section2, a longitudinal strake shop section 3 and a transverse beam shop 4where materials are accumulated and worked; a longitudinal strakeassorting shop section 5 where flat plates fabricated by theplate-jointing shop section 2 are assorted with longitudinal strakesmade by the longitudinal strake shop section 3; a transverse beamassorting shop section 6 where transverse beams made by the transversebeam shop section 4 are assorted with the combinations of plates andtransverse strakes; assembly shop sections 7,, 7 where flat blocks areassembled to specified size and structure; welding shop sections 8,, 8where the members of the flat blocks assembled in the assembly shopsections 7,, 7 are welded together; fitting shop sections 9, to 9 wherethe flat blocks welded in the welding shop sections 8,, 8 are finished;coating shop sections 10,, 10 where those of the flat blocks completedin the fitting shop sections which require coating are coated; adischarge section 11 through which completed flat blocks are conveyedout of the plant; and a spare section 12 where a flat block or blocksare working in any of the shop sections above mentioned are temporarilystored before being transferred to the next shop section as long as apreceding unit or units still remain in the next station. The shopsections disposed adjacent the conveying section 1 are provided with oneentrance each, through which the transfer truck 1, and a flat block orblocks can enter or leave the individual sections or through which aflat block or blocks can be transferred to or from the truck 1,.

In a flat block plant of the layout above described, flat blocks areconstructed by the following procedure. First, materials necessary forthe construction of blocks are piled and worked at the platejoining shopsection 2, longitudinal strake shop section 3, and transverse beam shopsection 4 to form jointed plates, longitudinal strakes and transversebeams. Next, the flat plates fabricated at the plate-jointing shopsection 2 are carried by the truck ll, in the conveying section ll intothe longitudinal strake assorting shop section 5, where longitudinalstrakes are erected on the flat plates. Then, the flat plates assortedwith the longitudinal strakes are conveyed by means of the truck 1, tothe transverse beam assorting shop section 6 and transverse beams areplaced on the flat plates already assorted with the longitudinalstrakes.

Thereafter, the flat plates combined with the longitudinal strakes andtransverse beams are conveyed by ,the truck 1, to the assembly shopsections 7,, 7 where the flat plates, longitudinal strakes, andtransverse beams in relative positions as specified are exactlypositioned as by tack welding, and the temporary assemblies are carriedby the truck l, to the welding shop sections 8,, 8 In these sections theblocks are welded at as many points of the members as feasible by theuse of automatic or semi-automatic welding machines. Next, theunfinished flat blocks fully welded in the welding shop sections 8,, 8are carried by the truck 1 to the fitting shop sections 9, to 9., sothat the unfinished parts are finished as the blocks proceed through thefour fitting shop sections. The finished blocks are then inspected.

The flat blocks that have passed the inspection are directly carried bythe truck 1, to the discharge section 11, from whence they aretransferred onto trailers or other transportation vehicles for deliveryout of the plant. These flat blocks that have passed the inspection andrequire coating are carried by the truck 1, to the coating shop sections10,, 10 where they are subjected to sandblasting and coating, and thenthe coated blocks are carried by the truck 1, to the discharge section11 and thence to the outside.

The spare section 12 of this flat block plant serves to provide a spacewherein a flat block or blocks under construction are temporarily placedwhen any preceding flat block or blocks are retained in between shop ingblock or blocks. It has no special or exclusive equipment of its own andmay be used in common with all of the shop sections.

The flat block plant of the layout above described eliminates thedisadvantages of ordinary layouts. In the construction of the flatblocks which constitue part of hull structure, it is noted that thebottom plating, transverse bulkheads, longitudnal bulkheads, and variousdecks have certain structural features or dissimilarities and involvedifferent particulars and amounts of work during the process ofconstruction. Therefore, when such blocks are carried on a line conveyorfor quantity production, the conveying speed is limited to that of theblock which requires a maximum of work and it makes retention of work offrequent transfer of labor inevitable. This problem is settled by thisinvention. Only if periods of retention time are given correspondinglyto the amounts of work required on the flat blocks in the individualshop sections, the frequency of transfer of labor can be minimized andthe variation of process which is unforeseeable can be isolatedlyabsorbed without practically affecting other blocks, for the greatconvenience from the viewpoint of process control.

In the flat block plant according to the invention, the shop sections ofthe same series as classified by the type of operations, e.g., theassembly shop sections 7,, 7

sections and hamper the smooth advance of the followwelding shopsections 8,, or coating shop sections 10,, 10 can be collectivelylocated in sufficiently adjacent and limited sites for high degree ofmechanization or efficient joint use of equipment. This renders itpossible to expect sharp reductions in the number of man-hours andinitial investment on equipment.

Further, in the flat block plant of the invention, finished blocks canbe delivered out irrespective of the order of work starting and,therefore, the blocks can be promptly completed in succession even whenthe start of work is delayed or the process is retarded by somedifficulty in securing the materials or by other reasons, without givingany adverse effect upon the construction of other flat blocks.

While the present invention has been described in conjunction withspecific embodiments thereof, the invention is in no way limited theretobut numerous modifications are possible without departing from thespirit and scope and of the invention. In brief, this invention providesa shipyard for constructing a work structure which is completed by acombination of a plurality of process steps, comprising a strip ofconveying section which is equipped with a conveying equipment adaptedto move straightly forward and backward, and specialized shop sectionsfor performing the individual process steps having entrances on thesides facing said strip of conveying section through which saidconveying equipment and/or work unit can enter or leave the individualshop sections, said specialized shop sections being located as if tosurround said conveying section. With the construction described, theindividual work units can be freely transferred by the conveyingequipment, so that specialized operations are performed in a smooth flowsystem. The operations proceed efficiently, process control isaccomplished with ease, and the construction cost of buildings and otherestablishments can be largely saved. These features of the shipyardaccording to this invention are remarkably contributory to theimprovement of efficiency in the shipbuilding industry.

What is claimed is:

I. An assembly-line type of shipyard comprising:

a. an elongated horizontal conveyor travel path upon which work piececomponents of a ships hull may be carried;

b. conveying means movable on said travel path in a directionlongitudinally of and transverse to said path for moving work piececomponents between and into discrete work stations;

0. a material collecting shop station at one end of said path;

d. a discharge shop station adjacent the other end of said path;

e. a plurality of discrete separate work shop stations situated on bothsides of said path intermediate its ends within which sequential work ona ships hull may be performed, each shop station having an entrancefacing said path and of such size as to accommodate said conveying meanswith work pieces situated thereon;

f. means in at least one work shop station for joining together at leasttwo work pieces;

g. means in another work shop station for applying a protective coatingto the work pieces previously joined; and

h. a spare shop station for temporarily storing joined work pieces inthe event that a subsequent work shop station is occupied by work piececomponents.

1. An assembly-line type of shipyard comprising: a. an elongatedhorizontal conveyor travel path upon which work piece components of aship''s hull may be carried; b. conveying means movable on said travelpath in a direction longitudinally of and transverse to said path formoving work piece components between and into discrete work stations; c.a material collecting shop station at one end of said path; d. adischarge shop station adjacent the other end of said path; e. aplurality of discrete separate work shop stations situated on both sidesof said path intermediate its ends within which sequential work on aship''s hull may be performed, each shop station having an entrancefacing said path and of such size as to accommodate said conveying meanswith work pieces situated thereon; f. means in at least one work shopstation for joining together at least two work pieces; g. means inanother work shop station for applying a protective coating to the workpieces previously joined; and h. a spare shop station for temporarilystoring joined work pieces in the event that a subsequent work shopstation is occupied by work piece components.